With the progress in the technological fields, all kinds of electronic elements have constantly upgraded operating ability, which also brings increased heat produced by the electronic elements during the operation thereof. Therefore, people demand more and more for heat sinks with improved performance. For the purpose of providing enhanced heat dissipating function, most of the conventional heat sinks will adopt a radiating fin assembly consisting of a plurality of sequentially stacked radiating fins. Researches have been constantly conducted to develop improved radiating fins, and a high-performance heat sink has become one of the most important targets in the industrial field. For example, among others, the central processing unit (CPU) of a computer produces the largest part of heat in the computer. The CPU would become slow in running when the heat produced and accumulated in the computer gradually increases. When the heat accumulated in the computer exceeds an allowable limit, the computer is subject to the danger of shutdown or even becoming seriously damaged. Moreover, to solve the problem of electromagnetic radiation, a case is used to enclose all the important computer components and elements therein. Therefore, it is very important to quickly dissipate the heat produced by the CPU and other heat-producing elements in the computer case.
FIG. 1A is a perspective view of a conventional thermal module, and FIG. 1B is a top view of a radiating fin assembly 1 included in the thermal module. As shown, the conventional thermal module includes a radiating fin assembly 1, which is formed by a plurality of sequentially stacked radiating fins 11. Generally, each of the radiating fins 11 is a cut sheet metal material with two opposite ends being bent toward the same side to form two flanges 111. The flanges 111 on a higher radiating fin 11 are pressed against a top face 11a of an adjacent lower radiating fin 11, such that a heat dissipating space 112 is formed between any two adjacent radiating fins 11. A cooling fan 12 is mounted to one longitudinal side of the radiating fin assembly 1 to face toward the heat dissipating spaces 112. When the cooling fan operates, it produces and forces cooling airflows 121 into the heat dissipating spaces 112 to carry heat away from the radiating fin assembly 1. Since the radiating fin assembly 1 is formed from a plurality of closely stacked radiating fins 11, the heat dissipating spaces 112 formed between two adjacent radiating fins 11 are extremely small in height. Meanwhile, the heat dissipating spaces 112 each have a relatively large depth to define a quite long path for the cooling airflows 121. As a result, the cooling airflows flowing through the heat dissipating spaces 112 are subject to increased pressure drop and slowed flowing speed, which have adverse influences on the heat dissipating efficiency of the thermal module.
In brief, the conventional radiating fin assembly and the thermal module formed therefrom have the following disadvantages: (1) providing only very narrow heat dissipating spaces; (2) having poor heat-exchange efficiency; (3) providing only low heat dissipating efficiency; (4) having quiet long cooling airflow paths; and (5) subjecting the cooling airflow to increased pressure drop.
It is therefore tried by the inventor to develop an improved radiating fin assembly and a thermal module formed from such radiating fin assembly to overcome the drawbacks in the conventional radiating fin assembly and the thermal module formed therefrom.